Patent GB-759523-A (GB)
Title: Extraction apparatus and method of operating same
Inventor: KOENIG PHILLIPP
IPC: B01D11/02
Filed: 1953-12-29
Abstract: <PICT:0759523/III/1> <PICT:0759523/III/2> In an apparatus for the extraction of solid materials, such as oil seeds or oil fruit, coffee, cocoa shells, cinchona bark, coals, tobacco, sugar cane, sugar beet, comprising a travelling liquid permeable or screen belt on which the material is repeatedly treated with extractant, side walls adapted to retain the material on the belt and partition walls which are adapted to subdivide the layer of the material on the belt transversely to the direction of the movement of the material and prevent or restrict slight quantities, the overflow of liquid from one section to the other, there are arranged beneath the belt a collecting tank or tanks for the solutions draining from the material, the tank or tanks being subdivided by walls at right-angles to the length of the belt and decreasing in height in a direction opposite to the direction of travel of the belt.  As shown in Fig. 1, the material to be extracted is conveyed into a charging bin 1 whence it is continuously fed by a discharging device 2 into extractor 3 in which is arranged an endless screen belt 4 moved by a drum 5 and stretched by a drum 6 and on which rests a chain of frames 7 which is guided over the wheel 12 and the drum 5 of the screen belt.  The material fed from the charging device to the chain of frames is deposited on screen belt 4 and falls, behind the wheel 12 of the screen belt 6, from the chain of frames into discharge device 13, from whence it is taken off for further treatment.  Beneath the upper part of screen belt 4 is placed collecting tank 14 with several compartments, e.g. 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h.  The fresh solvent is supplied to the material through sprinkler 15 and passes through the material to compartment 14a of the collecting tank whence it is again sprayed on to the material by a pump 16 and sprinkler 16a and passing through the material arrives back to compartment 14a. From compartment 14a the solution flows over partition wall 90a into compartment 14b, in quantities corresponding to the supply of solvent through sprinkler 15.  The solution is likewise circulated through the material to be extracted from 14b by means of feeding device 17 and sprinkler 17a and this is repeated, e.g. above the compartment 14c and 14d.  From the latter the excess of the solution flows over the sheet 91 to 14e and there the same circulation of the liquid takes place as in 14a up to 14d, but from 14e the excess of the solution flows in the direction of the moving material to compartment 14f, the solution passing from the latter into 14g is drawn off by pump 18 and fed to the drained material in order to be filtered and passes through the material to 14h from which it is conveyed by device 19 to filter 20 for fine filtration, the filtered solution flowing through pipes 21 into storage tank 22.  The liquid obtained in filters 20 is passed through pipes 23 into vessel 24 which also receives the solution conveyed from 14e by pump 25 through pipe line 25a and from which the solution passes through pipe line 26 into receiver bin 1 to moisten the material contained therein, the excess of the solution being directly passed from the container 24 on to the material through pipe line 27 and sprinkler 28, and the filtered solution may also flow through pipe 41 to pump 25.  In the modification shown in Fig. 3 an upper endless screen belt 4 driven over drum 5 and stretched by drum 6 and a lower endless screen belt 4a moving over the driving drum 4a and stretching drum 6a are provided which carry the chain of frames 7 propelled by the drum 12a and stretched by the reversing device 12, there being provided beneath the upper part of the lower screen belt 4a a further collecting tank 31 subdivided into compartments 31a, 31b, 31c, and 31d.  The material which is fed to the upper screen belt 4 and is filled into the upper part of the chain of frames 7 is carried by the screen belt and the chain of frames until, having passed drum 6, it falls on to the lower screen belt 4a and the lower part of the chain of frames and after passing through the lower part of the extraction device material arrives at the discharge device 13.  The fresh solvent is distributed over the material by sprinklers 32, flows through the material and is received in compartment 31a and is again fed to the material by a conveyer device 33 and sprinklers 34 and after passing through the material returns again to receiver 31a. The excess solution, the quantity of which approximately corresponds to the quantity of fresh solvent supplied by sprinklers 32, flows from receiver 31a over partition wall 92a into compartment 31b and by means of conveyer device 35 and sprinkler 36 is circulated through the material moving above compartment 31b, the excess of the solution flowing on over partition walls 92b into compartment 31c and above this and the following compartments the extraction is carried out as described above.  From the last compartment, e.g. 31d, the solution is fed by a conveyer 37 and sprinkler 38 to the material which is on its way from the upper to the lower extraction, a further sprinkler 39 being provided to spray the material falling on to the lower part of the chain of frames.  The excess of the solution in the last compartment, e.g. 31d of the lower extraction, which also may have a smaller or larger number of comparts, is passed for example by means of overflow pipe 40 to conveyers 16 or 17 and thence by means of sprinklers 16a and/or 17a sprayed on the material lying on the upper screen belt 4, the extraction on screen belt on the latter being similar to that described above.  In another embodiment (Fig. 4, not shown) a crushing unit is provided between the upper and lower screen belts to treat the material after extraction on the upper belt and before extraction on the lower belt.  Specification 680,728 is referred to.